special properties of plant cells

 Special Properties of Plant Cells:-

Among eukaryotic cells the most striking difference is between those of animals and plants. Plants have evolved a sedentary lifestyle and a mode of nutrition that means

they must support a leaf canopy. Their cells are enclosed within a rigid cell wall that gives

shape to the cell and structural rigidity to the organism. This is in contrast to the flflexible boundaries of animal cells. Plant cells frequently contain one or more vacuoles

that can occupy up to 75% of the cell volume. Vacuoles accumulate a high concentration

of sugars and other soluble compounds. Water enters the vacuole to dilute these sugars,

generating hydrostatic pressure that is counterbalanced by the rigid wall. In this way the

cells of the plant become stiff or turgid, in the same way that when an inner tube is inflflated

inside a bicycle tire the combination becomes stiff. Vacuoles are often pigmented, and

the spectacular colors of petals and fruit reflflect the presence of compounds such as the

purple anthocyanins in the vacuole. Cells of photosynthetic plant tissues contain a special

organelle, the chloroplast, that houses the light-harvesting and carbohydrate-generating

systems of photosynthesis. Plant cells lack centrosomes although these are found in many algae.